The present invention relates generally to a packet switching testing method and a packet switching testing apparatus for testing an operation of a packet switching device. The present invention relates, more particularly, to a packet switching testing method and a packet switching testing apparatus that are capable of attaining down-sizing of the apparatus and readily testing the packet switching device.
The packet switching device decomposes communications information packetwise which is given from one terminal. The packet switching device then adds, to each decomposed packet, path information containing a virtual channel identifier and a virtual path identifier. The packet switching device switches a signal path to transmit each packet to some relay circuit. The packet switching device transfers the packet from one terminal to the other terminal connected to the relay circuit.
The packet switching device described above has to transmit the packet without any error. For an assurance of a packet quality, the packet switching testing apparatus performs a test for an operation of the packet switching device.
On the transmitting side of this packet switching testing apparatus, a random pattern generator generates a plurality of random patterns representing the communications information. A packet section decomposes the plurality of generated random patterns into each random pattern. The packet section adds the path information to each random pattern, thereby generating packet data. The packet data is supplied to the packet switching device.
On the receiving side of the packet switching testing apparatus, a depacket section detects the packet data from the packet switching device in accordance with the path information. The depacket section fetches each random pattern out of the packet data. Then, an error detector detects an error in the random pattern. The packet switching device is tested based on the detection of the error in the random pattern.
When testing the plurality of packet switching devices or a plurality of packages, however, a plurality of packet switching testing apparatuses are required corresponding thereto. Further, when a plurality of I/O highways are connected to the single packet switching device or the single package, the plurality of packet switching testing apparatuses are needed corresponding to the plurality of I/O highways. This results in such a problem that the packet switching testing apparatus remarkably increases in size.
Further, the conventional packet switching testing apparatus is incapable of performing multiplex and demultiplex converting processes of the packet data on each highway and an inter-highway path switching process.
Besides, if the packet switching device effects a packet disposal and a packet loss, the packet data disappear with the packet disposal when the packet switching testing apparatus detects the random patterns. For instance, the packet section adds packet headers such as the above path information to random patterns a1, b1, c1, d1 of the serial random patterns. Packet data P1, P2, P3, P4 are thereby generated.
The packet switching device forcibly disposes of the packet data P2. A depacket section fetches the original random pattern out of each packet data. There lacks the random pattern in the packet data P2 disposed of. For this reason, the random pattern c1 is inputted to an error detector after inputting the random pattern a1. Namely, there arises a problem in which the random patterns are out of synchronism, and an error in the random pattern can not be accurately detected.